The dorsal skin structure contributes to the surface bacteria populations of Sunda Porcupine (Hystrix javanica)

Abstract

Skin becomes the largest organ in the body and protects its own inner layer. The structure and chemical composition of the skin contribute to skin condition and affect the habitat of certain bacteria. The Sunda Porcupine is one of endemic animals of Indonesia which possesses quill as the main derivate of its skin and as a defence tool against predators. The present study used nine adults (five females and four males) of Sunda Porcupine and aimed to observe the correlation of skin structure with bacterial population at the surface level. The skin was wavy due to the protrusion of quill follicle orifices on the skin surface and formed clusters. The skin of Sunda Porcupine was also wrinkled and had a lot of flakiness. Histologically, the skin was composed of epidermis, dermis, hypodermis and subcutaneous muscle. The quill follicles and their properties were the dominant structure component of the skin. No sweat gland was observed in the skin of the Sunda Porcupine, and sebaceous gland was found only around quill and hair follicles. The bacterias identified in the skin were Staphylococcus aureus, S. epidermidis, Micrococcus sp. and Salmonella sp. When compared, the bacterial population was higher in the lumbosacral region than in the thoracodorsal region, but the difference was not significant. The density of quill clusters was negatively correlated to the bacterial population. It was suggested the structure of the skin has contribution to bacterial population in dorsal trunk of the Sunda Porcupine.

Vitamin E (Alpha Tocopherol) Level in the Dorsal Skin of Sunda Porcupine (Hystrix javanica)

“…Skin with high density of sebaceous glands will have higher alpha tocopherol content (Thiele et al, 1999). Our previous studies showed that sebaceous gland density in TD region is higher than in LD region (Prawira et al, 2018b). The difference in level between male TD and female TD may also be influenced by different hormonal activity between the sexes affecting the activity of the sebaceous glands (Cunliffe & Forster, 1987;Fritsch et al, 2001).…”

“…Skin characteristics in the LS region showed lower density of the quill clusters than in the TD region (Prawira et al, 2018b) allow many parts of the skin to be exposed to the environment such as sunlight, soil, dust, etc. more than the TD region.…”

“…The skin of Sunda Porcupine has quills as main derivatives of varying sizes and densities in various parts of the body. The quill clusters in the TD region is smaller but higher density compared to the LS region which is larger but lower density (Prawira et al, 2018b) resulting in broader skin surface exposed to the environment. In addition, higherquillcluster density in the TD region has implications for higher sebaceous gland density when compared to the LS region due to the sebaceous gland are found only in quill and hair follicle (Prawira et al, 2018a;2018b) and might be resulting in different sebaceous gland activity in eachregion.…”

Lectin histochemical study of the quill sebaceous gland in the dorsal skin of the Sunda porcupine (Hystrix javanica)

“…The quills of all porcupine species are larger, stiffer and stronger than its hairs and act as means of self-defense from predators or other threats (Mohr 1965;Myers 2001;van Weers 1983). Previously we exhibit that the appearances of dorsal skin surface of the porcupine is wavy due to protrusion of quill follicles in the form of clusters and varying in size according to the location and quill type (Prawira et al 2018b). The quill follicles are known as the dominant structure in the skin of this species (Prawira et al 2018a).…”

“…Sizes of the sebaceous glands of quills were relatively larger compared to the hairs' glands. Glandular lobules of quill sebaceous gland were composed of well-developed sebaceous acinar cells with lipid vacuoles varying in size (Prawira et al 2018b).…”